The invention relates to a web registration control for web handling apparatus having motive means operatively moving a web containing repetitive indicia through a sequencially operating function apparatus performing repetitive operations on the web corresponding to the repetitive indicia.
Web material, such as paper, film, tape etc., is employed for various uses in the printing industry, paper converting industry, packaging industry and the like. Frequently, such web material is continuously fed through processing machinery and subjected to one or more processing operations thereon. For example, a function apparatus might include a knife which is sequentially operated to sever the web material into sheets of substantially equal length for further use or processing. As another example, the function apparatus might print or emboss such film with repetitive patterns or written material. As another example, the function apparatus might puncture the web material. Thus whatever function is being applied to the web material, it is important that the repetitive operations of the function apparatus are performed in registration with appropriate web sections. It has been customary in the web processing industry to utilize repetitve indicia on the web which are detected for controlling the operation of the web handling apparatus and, when an out of register condition is found, to modify the operation of such web handling apparatus to attempt to regain registration.